16 
whatever, with the pole of the earth in its present position, a 
sufficiency of light and heat at Spitzbergen could not possibly 
have been received from the sun. 
But there is another bond of union between the different 
planets ; and that is, the nearer each is to the sun the shorter 
is its year. The first calendar of which we have record 
gives the year as 304 days. Mercury performs his periodical 
revolution in about 88 days — Venus in 224 days, so that if the 
earth's orbit has been nearer the sun, and the tropics at the 
pole, we have at once the heat required by Brongniart, the 
year also proportionably shorter (and it may have been consi- 
derably shorter), and therefore these long periods of time 
indulged in by geologists may have consisted of years of not 
more than 200 or 230 days, and thus the frequent reappear- 
ance of the sun in these northern regions would as frequently 
reproduce the numerous coal seams of our coal districts, and 
especially those double, or even many beds of coal one 
placed above the other ; as in the Barnsley seam, there are 
five different beds, total nine feet thick, representing five 
different qualities, and could only have been grown in 
different years. In the Yorkshire coal field there are about 
fifty different beds, whose total thickness is 84 feet, contain- 
ing above 100,000 tons per acre where the coal district is in 
its full thickness, having all the 50 seams in situ. 
Ascending to the Permian system of Murchison, so well 
developed around Doncaster, — the cutting in the South York- 
shire Railway to Conisbro' Castle from Hexthorp, being the 
best section in England, — what marks are there of expansion 
or increase in the earth's orbit ? 
The Permian beds consist of — 
1. Rothe todte liegendie, of Conisbro' Castle. 
2. Magnesian limestone, of Levitt Hagg. 
3. Red marl and gypsum, in the cutting opposite 
Warmsworth. 
